11999988 has 240 divisors, whose sum is σ = 43257984. Its totient is φ = 2799360.

The previous prime is 11999987. The next prime is 11999989. The reversal of 11999988 is 88999911.

It is an interprime number because it is at equal distance from previous prime (11999987) and next prime (11999989).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11999987) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 324306 + ... + 324342.

Almost surely, 2^11999988 is an apocalyptic number.

11999988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11999988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21628992).

11999988 is an abundant number, since it is smaller than the sum of its proper divisors (31257996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11999988 is a wasteful number, since it uses less digits than its factorization.

11999988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 73 counting only the distinct ones).

The product of its digits is 419904, while the sum is 54.

The square root of 11999988 is about 3464.0998830865. The cubic root of 11999988 is about 228.9427721964.

11999988 divided by its sum of digits (54) gives a palindrome (222222).

It can be divided in two parts, 11 and 999988, that added together give a palindrome (999999).

The spelling of 11999988 in words is "eleven million, nine hundred ninety-nine thousand, nine hundred eighty-eight".